JPH0453845Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a collect chuck for gripping a bar-shaped workpiece or tool within the tip of a spindle in a machine tool such as a lathe.

[Prior Art] A collet chuck is a device for attaching a bar-shaped workpiece with a circular cross section or a tool with a cylindrical handle to the main shaft of a machine tool, etc., and a collet chuck is generally a hollow chuck made of hardened steel. A gripping portion is created by making multiple cuts in the axial direction of the cylindrical body from one end, and the outside of the gripping portion is a tapered surface that fits into the tapered hole of the outer holder. By moving the cylindrical body and the holder relative to each other in the axial direction using a manual screwing tool or power from the main shaft, the tapered surface converts the movement into radial movement to close the gripping part and clamp it inside. It is now able to grasp objects that are present.

FIGS. 9 and 10 show a conventional example of a screw-in type using a hand tool.

In the figure, a holder 101 as an outer member has an inner hole 103 with a tapered hole 102 formed at its tip, and a female threaded portion 104 is provided at the back of this inner hole 103. The chuck main body 110 is made of a cylindrical body having a male threaded portion 111 at the base, and three axial cuts 112 are provided at equal intervals in the circumferential direction from the middle portion to the tip portion. A tapered surface 113 is integrally formed on the outer periphery of the cut portion at the middle in the axial direction, and a bolt head-shaped tool receiving portion 114 is further integrally formed at the tip.

The chuck body 110 is located in the inner hole 1 of the holder 101.
03, and its male threaded portion 111 is screwed into the female threaded portion 104 of the holder 101. When a rod-shaped workpiece or the like is inserted into the center hole 115 of the chuck body 110 and the bolt head-shaped tool receiving portion 114 is turned and tightened with a tool such as a wrench, the male threaded portion 10
4 and the female threaded portion 111 and the relative movement in the axial direction causes the tapered surface 113 to fit into the tapered hole 10.
As a result, the tapered surface 113 is pushed radially inward and the center hole 115 is closed.
The rod-shaped workpiece inside is tightly gripped by tightening from three sides around it.

[Problems to be solved by the invention] In conventional collect chucks, the slits reach the tip of the chuck body and are opened, so when the chuck is closed, the movement of the gripping part is caused by the movement of the non-opening side of the slits. This is a rotational movement in the radial direction of the main body around the base, and the inner wall of the central hole for gripping a bar-shaped workpiece does not move parallel to the axis when the chuck is closed. Therefore, in order to maintain the required run-out accuracy, the center hole must be formed with extremely high machining accuracy relative to the outer diameter of the object to be gripped. It is common for a separate chuck to be prepared for each object, and different outer diameters result in circumferential scratches on the internal hole surface of the chuck by the end of the object.

In addition, when screwing in the chuck body with a manual tool as shown in Figures 9 and 10 above, if a tool of the type that grips from two directions, such as a spanner or wrench, is used, the chuck will be split into three parts. The force from the tool is not evenly transmitted to all three parts of the hex bolt head-shaped tool receiving part 114, and excessive force is applied to a specific part of the three parts, causing one of the three parts to break down. The base could be damaged by twisting. In this case, even if a box wrench or the like that grips from the entire circumference is used as a tool, when the chuck is strongly tightened, uneven deflection occurs from the head to the base of the chuck due to twisting, making it difficult to chuck with high accuracy.

The purpose of this invention is to solve these problems and to make the gripping part movable almost parallel to the axis, and also to be able to cut when rotating the tool receiving part at the tip of the chuck with a tool. To provide a collection chuck in which excessive force or uneven force is not applied to a specific part of a part.

[Means for Solving the Problems] According to this invention, the gripping portion is formed by making a plurality of axial cuts in the body of the cylindrical body at intervals in the circumferential direction, and the gripping portion is In a collect chuck whose outer periphery is formed into a tapered surface and is fitted into a tapered hole of an outer member, and the gripping portion is closed in the radial direction by relative movement in the axial direction with the outer member, both ends of the slit in the axial direction are formed into a cylindrical shape. The ends are terminated without reaching both axial ends of the cylindrical body, and a continuous annular portion is formed in the circumferential direction at both axial ends of the cylindrical body, and the integral annular portion at both ends and the tapered outer circumference are formed. The above-mentioned problem is achieved by forming the portion between the grip portion and the grip portion into a thin elastic portion.

[Function] The collect chuck of this invention has a structure in which the grip portion, which is movable in the radial direction by the cut, is supported on both sides in the axial direction by integral annular portions at both ends of the cut. Since both of these annular parts have high rigidity against deformation in the radial direction, the gripping part that is bridged between them is elastically deflected on both sides in the axial direction when compressive force is applied in the radial direction. It will close with a parallel displacement.

It should be noted that such a parallel displacement of the gripper makes it possible to accept virtually any object having a thickness that falls within the permissible range of displacement of the gripper. That is, the invention provides a substantially variable collection chuck.

On the other hand, when turning the tool holder at the tip of a chuck using a hand tool, the collector chuck of this invention can use the integral annular part at the end of the cylindrical body as the tool holder. Of course, even when using a tool that pinches from two directions, by pinching the annular part with the tool and rotating it,
Since force is evenly distributed from the annular part to the gripping parts divided by the cuts, excessive force will not be applied to any particular part.

A concrete example of this invention will be described below with reference to the drawings.

[Example] Fig. 1, Fig. 2, and Fig. 3 show an example applied to a manual screw-in type.

In the figure, a holder 1 as an outer member has an inner hole 3 with a tapered hole 2 formed at its tip, and a female threaded portion 4 is provided at the back of this inner hole 3. The chuck body 10 is made of a cylindrical body with a male threaded portion 11 at the base, and an axial cut 1 in the middle body.
Three pieces 2 are provided at equal intervals in the circumferential direction. A tapered surface 13 is integrally formed on the outer periphery of a thick part in the middle of the cut portion in the axial direction, and thin parts 16 and 17 are formed on both sides in the axial direction, respectively. Further, a bolt head-shaped tool receiving portion 14 is integrally formed at the tip. The slits 12 end without reaching both ends of the main body 10, and in the illustrated example, the slits 12 are located near both ends of both thin-walled portions 16 and 17.
The end of is located.

The chuck body 10 is inserted into the inner hole 3 of the holder 1, and its male threaded portion 11 is screwed into the female threaded portion 4 of the holder 1. Center hole 1 of chuck body 10
When a rod-shaped workpiece or the like is inserted into 5 and the bolt head-shaped tool receiving part 14 is turned and tightened with a tool such as a wrench, relative movement in the axial direction occurs due to the screw engagement between the male threaded part 4 and the female threaded part 11. As a result, the tapered surface 13 enters the tapered hole 2, and as a result, the tapered surface 13
is pushed radially inward. At this time, both thin parts 1
By bending 6 and 17 together, the tapered surface 1
The corresponding inner hole wall surface of No. 3 moves parallel to the axis and the center hole No. 1
5 is closed, and the rod-shaped workpiece inside is tightly gripped by tightening from three sides around it.

FIG. 4 shows a modification of the above embodiment, in which the chuck body 40 has two large and small tapered surfaces 43a, 43b.
, and two-step tapered holes 32a and 32b corresponding to the holder 31 are also provided to increase the axial dimension of the gripping portion to enable even more stable and firm chucking. In addition, the reference numeral 34 in Figure 4
41 is the female threaded part of the holder, 42 is the male threaded part of the chuck body, 42 is the cutout, 44 is the tool receiving part, 45
indicates a center hole, and 46 and 47 indicate thin-walled portions, and since these are the same as in the previous embodiment, their explanation will be omitted.

FIGS. 5 and 6 show another embodiment of this invention, which is of a push-in type using a hand tool. That is, holder 5
1 has an inner hole 53 without a female thread, and a tapered hole 52 is formed at the tip thereof. On the other hand, a male threaded portion 55 is formed on the outer surface of the holder 51, and a female threaded portion 57 of a pushing ring 56 that covers the holder from the distal end side is screwed into this male threaded portion 55.

The chuck main body 60 is a cylindrical body having partially cylindrical annular portions 61 and 64 at both ends in the axial direction, and is slidably inserted into the inner hole 53 of the holder 51. Three directional cuts 62 are provided at equal intervals in the circumferential direction. Tapered surface 6 on the outer periphery in the thick part in the middle of the cut part
3 is provided, and this tapered surface 63 is the holder 5.
1, and its front end surface 68 corresponds to the shoulder 58 inside the cap 56 of the holder 51. As in the previous embodiment, both sides of the cut portion in the axial direction are thin-walled portions 66 and 67.

In this embodiment, the inner hole 5 of the holder 51
After inserting the chuck main body 60 into the chuck 3, cover the cap 56 and insert the female threaded part 57 into the holder 51.
It is screwed into the male threaded part 55 of. When the tool receiving part 59 formed on the outer periphery of the cap 56 is turned and tightened with a hand tool, the male threaded part 55 of the holder 51 and the female threaded part 57 of the cap 56 are screwed together, and the cap 5 is closed.
6 pushes the front end surface 68 of the chuck body through the shoulder 58, thereby causing the tapered surface 63 to enter into the tapered hole 52, and as a result, the tapered surface 63 moves radially inward. You will be forced into it. At this time, both the thin parts 66 and 67 bend together, so that the corresponding inner hole wall surface of the tapered surface 63 moves parallel to the axis, and the center hole 65 is closed.
The rod-shaped workpiece inside is tightly gripped by tightening from three sides around it.

FIGS. 7 and 8 show yet another embodiment of this invention. In this example, the chuck main body 80 is rotatably held within the holder 71, and when the chuck is tightened, a rod 90 is inserted between the two to prevent rotation, thereby making them non-rotatable relative to each other. The chuck main body 80 includes a male threaded portion 81, an annular portion 88, a thin wall portion 86a, a large diameter tapered surface portion 83a, and a thin wall portion 8.
6b, a small-diameter tapered surface portion 83b, a thin wall portion 87, and an annular tip portion 84 are formed in this order from the base, and both thin wall portions 86a, b and 87 are formed between both tapered surface portions 8.
3a, 83b, three axial cuts 82 are provided at equal intervals in the circumferential direction. Further, a push-in sleeve 76 is inserted into the annular gap between the holder 71 and the chuck body 80, and a female threaded portion 77 formed on the inner surface of the tip end of the sleeve 76 is screwed into the male threaded portion 81 of the chuck body 80. Inside the sleeve 76, large and small tapered holes 78a and 78b are provided in a stepped manner, and are in contact with large and small tapered surface portions 83a and 83b of the chuck body 80, respectively. A tool receiving portion 79 is formed on the outer periphery of the tip of the sleeve 76 .

In this embodiment, the sleeve 76 is attached to the chuck body 80 by turning the sleeve 76 with a tool.
This causes the tapered surface portions 83a and 83b to be displaced in the radial direction, thereby closing the center hole 85 and tightening the internal workpiece from three sides.

In each of the embodiments described above, the case where the chuck main body is divided into three parts is described.
Needless to say, it can be of any arbitrary structure, such as quarter or six. Furthermore, although the central hole of the chuck body has been described as a circular hole, it may be formed into, for example, a hexagonal hole or the like depending on the cross-sectional shape of the object to be chucked.

[Effects of the invention] As described above, according to this invention, the gripping part of the chuck body moves almost parallel to the axis, so it is possible to substantially change the chuck to accommodate slight differences in the outer diameter of the object to be chucked. A correct chuck can be realized, and even in the case of a type in which tightening is performed by holding the tip of the chuck body with a tool and turning it, it is possible to prevent excessive force from being applied to only a part of the cut part, making it stable and causing damage. It is possible to make it something less scary.

[Brief explanation of the drawing]

Figure 1 is a side view of a manual screw-in type collet chuck according to an embodiment of this invention, showing the holder part in cross section, Figure 2 is an end view of the chuck body, and Figure 3 is viewed from the XOX line in Figure 2. 4 is a cross-sectional view of the chuck body along the line, and FIG. 4 is a cross-sectional view showing a modified example.
Fig. 5 is a sectional view showing another embodiment of this invention, Fig. 6 is an end view thereof, Fig. 7 is a sectional view showing still another embodiment of this invention, and Fig. 8 is an end view thereof. 9 is a side view of a conventional manual screw-in type collection chuck, and FIG. 10 is an end view of the chuck body. Explanation of symbols of main parts, 1...Holder, 2...
...Tapered hole, 10...Chuck body, 12...
Cut, 13...Tapered surface, 14...Tool receiving part (tip annular part), 15...Center hole, 16, 17
...thin section.

Claims (1)

[Claims for Utility Model Registration] A gripping portion is formed by making a plurality of cuts in the body of a cylindrical body at intervals in the circumferential direction,
In the collect chuck, the outer periphery of the grip portion is formed into a tapered surface and is fitted into a tapered hole of an outer member, and the grip portion is closed in the radial direction by relative movement in the axial direction with the outer member, wherein both ends of the slit in the axial direction The parts are terminated without reaching both sides of the axial direction of the cylindrical body, and a continuous annular part is formed in the circumferential direction at both axial ends of the cylindrical body, and the integral annular part at both ends and A collection chuck characterized in that a portion between the outer circumferentially tapered gripping portion and the gripping portion is formed into a thin elastic portion that can be elastically deformed by an external force in the radial direction.